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Database-oriented storage based on LMDB and linear octree for massive block model 被引量:6
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作者 毕林 赵辉 贾明涛 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2016年第9期2462-2468,共7页
Data organization requires high efficiency for large amount of data applied in the digital mine system. A new method of storing massive data of block model is proposed to meet the characteristics of the database, incl... Data organization requires high efficiency for large amount of data applied in the digital mine system. A new method of storing massive data of block model is proposed to meet the characteristics of the database, including ACID-compliant, concurrency support, data sharing, and efficient access. Each block model is organized by linear octree, stored in LMDB(lightning memory-mapped database). Geological attribute can be queried at any point of 3D space by comparison algorithm of location code and conversion algorithm from address code of geometry space to location code of storage. The performance and robustness of querying geological attribute at 3D spatial region are enhanced greatly by the transformation from 3D to 2D and the method of 2D grid scanning to screen the inner and outer points. Experimental results showed that this method can access the massive data of block model, meeting the database characteristics. The method with LMDB is at least 3 times faster than that with etree, especially when it is used to read. In addition, the larger the amount of data is processed, the more efficient the method would be. 展开更多
关键词 block model linear octree lightning memory-mapped database mass data access digital mine etree
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Distinction of self-synchronous scrambled linear blockcodes based on multi-fractal spectrum 被引量:2
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作者 xinhao li min zhang +1 位作者 shu'nan han quan yuan 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2016年第5期968-978,共11页
This study proposes a novel multi-fractal spectrumbasedapproach to distinguish linear block codes from its selfsynchronousscrambled codes. Given that the linear block codeand self-synchronous scrambled linear block co... This study proposes a novel multi-fractal spectrumbasedapproach to distinguish linear block codes from its selfsynchronousscrambled codes. Given that the linear block codeand self-synchronous scrambled linear block code share the propertyof linear correlation, the existing linear correlation-basedidentification method is invalid for this case. This drawback can becircumvented by introducing a novel multi-fractal spectrum-basedmethod. Simulation results show that the new method has highrobustness and under the same conditions of bit error, the lowerthe code rate, the higher the recognition rate. Thus, the methodhas significant potential for future application in engineering. 展开更多
关键词 linear block code self-synchronous scrambled code multi-fractal spectrum statistical physics algorithm.
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BLOCK BIDIAGONALIZATION METHODS FOR MULTIPLE NONSYMMETRIC LINEAR SYSTEMS 被引量:1
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作者 Dai Hua(戴华) 《Numerical Mathematics A Journal of Chinese Universities(English Series)》 SCIE 2001年第2期209-225,共17页
The symmetric linear system gives us many simplifications and a possibility to adapt the computations to the computer at hand in order to achieve better performance. The aim of this paper is to consider the block bidi... The symmetric linear system gives us many simplifications and a possibility to adapt the computations to the computer at hand in order to achieve better performance. The aim of this paper is to consider the block bidiagonalization methods derived from a symmetric augmented multiple linear systems and make a comparison with the block GMRES and block biconjugate gradient methods. 展开更多
关键词 NONSYMMETRIC linear systems MULTIPLE right-hand sides block ITERATIVE methods.
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THERMO-RESPONSIVE BLOCK COPOLYMERS BASED ON LINEAR-TYPE POLY(ETHYLENE GLYCOL):TUNABLE LCST WITHIN THE PHYSIOLOGICAL RANGE 被引量:1
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作者 Guo-liang Yue Qian-ling Cui +2 位作者 Yu-xi Zhang Er-jian Wang 吴飞鹏 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2012年第5期770-776,共7页
Therrno-responsive block copolymers poly(ethylene glycol)-block-poly(N-acryloyl-2,2-dimethyl-1,3-oxazolidine), PEG-b-PADMO, based on linear PEG were prepared via a versatile reversible addition-fragmentation chain... Therrno-responsive block copolymers poly(ethylene glycol)-block-poly(N-acryloyl-2,2-dimethyl-1,3-oxazolidine), PEG-b-PADMO, based on linear PEG were prepared via a versatile reversible addition-fragmentation chain transfer (RAFT) polymerization, PEG22 (Mw = 1000) was used as the hydrophilic component, whose dehydration was the main driving force for the phase transition of these copolymers, as demonstrated by the tH-NMR spectra. Their lower critical solution temperatures (LCSTs) could be tuned in the range of 20℃ to 35℃, by adjusting the degree of polymerization (DP) of PADMO between 14-27. Furthermore, a sharp phase transition at ca. 33℃, close to the physiological temperature with minimal hysteresis, was observed for the PEGzz-b-PADMO14 copolymer. Moreover, excellent reversibility and reproducibility were displayed for the same copolymer over 10 cycles of repeated temperature change between 25℃ (below the LCST) and 40℃ (above the LCST). 展开更多
关键词 THERMO-RESPONSIVE block copolymers linear PEG Phase transitions.
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A Relaxed Greedy Block Kaczmarz Method for Solving Large Consistent Linear Systems 被引量:2
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作者 Yimou Liao Feng Yin Guangxin Huang 《Journal of Applied Mathematics and Physics》 2021年第12期3032-3044,共13页
Many problems in science and engineering require solving large consistent linear systems. This paper presents a relaxed greedy block Kaczmarz method (RGBK) and an accelerated greedy block Kaczmarz method (AGBK) for so... Many problems in science and engineering require solving large consistent linear systems. This paper presents a relaxed greedy block Kaczmarz method (RGBK) and an accelerated greedy block Kaczmarz method (AGBK) for solving large-size consistent linear systems. The RGBK algorithm extends the greedy block Kaczmarz algorithm (GBK) presented by Niu and Zheng in <a href="#ref1">[1]</a> by introducing a relaxation parameter to the iteration formulation of GBK, and the AGBK algorithm uses different iterative update rules to minimize the running time. The convergence of the RGBK is proved and a method to determine an optimal parameter is provided. Several examples are presented to show the effectiveness of the proposed methods for overdetermined and underdetermined consistent linear systems with dense and sparse coefficient matrix. 展开更多
关键词 linear Consistent Systems Convergence Properties Relaxed Greedy block Kaczmarz
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Linear/branched Block Polyethylene Produced by a-Diimine Nickel(Ⅱ)Catalyst and Bis(phenoxy-imine)Zirconium Binary Catalyst System in the Presence of Diethyl Zinc 被引量:1
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作者 Ding-Ding Zhao Yan-Hui Hou +3 位作者 Ke-Ning Zong Mi-Mi Cui Bin-Yuan Liu Min Yang 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2021年第12期1581-1589,共9页
In order to promote development of linear/branched block polyethylenes based on new catalytic systems,we synthesized a novel a.dimine nickel(Ⅱ)complex with isopropyl substituents on ortho-N-aryl and hydroxymethyl phe... In order to promote development of linear/branched block polyethylenes based on new catalytic systems,we synthesized a novel a.dimine nickel(Ⅱ)complex with isopropyl substituents on ortho-N-aryl and hydroxymethyl phenyl substituents on para-Naryl structures.The activity of a-dimine nickl(Ⅱ)catalyst was 3.02x10^(6)g-mol_(ni)^(-1)·h^(-1) at 70℃,and resultant polyethylene possessed 135/1000C branches.The linear/branched block polyethylenes were synthesized from ethylene polymerization catalyzed by the a-dimine nicke(Ⅱ)complex/bis(phenoxy-imine)zirconium in the presence of diethyI zinc.With the addition of ZnEtz(from 0 to 400),the melting peak of resultant polyethylene changed from a single melting peak to bimodal melting peaks.The molecular weights of resultant polyethylene ranging from 26.8 kg/mol to 17.1 kg/mol and PDI values varying gradually from 24.4 to 15.2 were obtained vla adjusting ZnEt;equiv.and molar ratio of two catalysts.In addition,the branching degree of the polyethylene increased from 13/1000C to 56/1000 with the increase of the proportion of a dimine nickel(Ⅱ)catalyst.Using this binary catalyst system,the reaction temperature of chain shutting polymerization can be carried out at 70℃,which is more conducive to industrial application. 展开更多
关键词 Chain shuttling polymerization linear/branched block polyethylene a-Diimine nickel Bis(phenoxy-imine)zirconium Ethylene
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Optimal and suboptimal structured algorithms of binary linear block codes
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作者 Yijun Luo Jin Li 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2011年第6期1010-1014,共5页
The optimal and suboptimal structured algorithms of linear block codes from the geometrical perspective are represented.The minimum distance and weight property lemmas and the theorem are proved for the generator matr... The optimal and suboptimal structured algorithms of linear block codes from the geometrical perspective are represented.The minimum distance and weight property lemmas and the theorem are proved for the generator matrix.Based upon the property of generator matrix,the structured algorithms of linear block codes are demonstrated.Since the complexity of optimal structured algorithm is very high,the binary linear block codes is searched by using the suboptimal structured algorithm.The comparison with Bose-Chaudhuri-Hocquenqhem(BCH) codes shows that the searched linear block codes are equivalent on minimum distance and can be designed for more block lengths.Because the linear block codes are used widely in communication systems and digital applications,the optimal and suboptimal structured algorithms must have great future being widely used in many applications and perspectives. 展开更多
关键词 channel coding linear block codes generator matrix minimum distance.
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A BLOCK VARIANT OF THE GMRES METHOD FOR UNSYMMETRIC LINEAR SYSTEMS
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作者 GUANGYE LI CRAY RESEARCH, INC.(55F LONE OAK DRIVE EAGAN, MN 55121, USA FAX: 612-683-5276, E-MAIL: GLI@CRAY.COM) 《Wuhan University Journal of Natural Sciences》 CAS 1996年第Z1期508-514,共7页
Iterative methods that take advantage of efficient block operations and block communications are popular research topics in parallel computation. These methods are especially important on Massively Parallel Processors... Iterative methods that take advantage of efficient block operations and block communications are popular research topics in parallel computation. These methods are especially important on Massively Parallel Processors (MPP). This paper presents a block variant of the GMRES method for solving general unsymmetric linear systems. It is shown that the new algorithm with block size s, denoted by BVGMRES(s,m), is theoretically equivalent to the GMRES(s. m) method. The numerical results show that this algorithm can be more efficient than the standard GMRES method on a cache based single CPU computer with optimized BLAS kernels. Furthermore, the gain in efficiency is more significant on MPPs due to both efficient block operations and efficient block data communications. Our numerical results also show that in comparison to the standard GMRES method, the more PEs that are used on an MPP, the more efficient the BVGMRES(s,m) algorithm is. 展开更多
关键词 iterative method unsymmetric linear system block algorithm parajlel computation.
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Linear Dispersion Orthogonal Space-Time Block Codes
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作者 高明 葛建华 李靖 《Journal of Beijing Institute of Technology》 EI CAS 2010年第3期357-361,共5页
A new architecture of space-time codes as a combination of orthogonal space-time block codes (OSTBC) and linear dispersion codes (LDC) is proposed in order to improve the bit error rate(BER) performance of OSTBC... A new architecture of space-time codes as a combination of orthogonal space-time block codes (OSTBC) and linear dispersion codes (LDC) is proposed in order to improve the bit error rate(BER) performance of OSTBC.The scheme proposed is named linear dispersion orthogonal space-time block codes (LDOSTBC).In LDOSTBC scheme,firstly,the data is coded into LDC codewords.Then,the coded LDC substreams are coded into OSTBC codewords again.The decoding algorithm of LDOSTBC combines linear decoding of OSTBC and ML decoding or suboptimum detection algorithms of LDC.Compared with OSTBC scheme when the rate of LDC is MtR,the performance of LDOSTBC scheme can be improved without decreasing the data rate,where Mt is the number of transmit antennas and R is the spectral efficiency of the modulation constellation.If some rate penalty is allowed,when the rate of LDC is less than MtR the performance of LDOSTBC can be improved further. 展开更多
关键词 space-time coding linear dispersion codes (LDC) orthogonal space-time block codes (OSTBC)
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Two-Parameter Block Triangular Splitting Preconditioner for Block Two-by-Two Linear Systems
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作者 Bo Wu Xingbao Gao 《Communications on Applied Mathematics and Computation》 EI 2023年第4期1601-1615,共15页
This paper proposes a two-parameter block triangular splitting(TPTS)preconditioner for the general block two-by-two linear systems.The eigenvalues of the corresponding preconditioned matrix are proved to cluster aroun... This paper proposes a two-parameter block triangular splitting(TPTS)preconditioner for the general block two-by-two linear systems.The eigenvalues of the corresponding preconditioned matrix are proved to cluster around 0 or 1 under mild conditions.The limited numerical results show that the TPTS preconditioner is more efficient than the classic block-diagonal and block-triangular preconditioners when applied to the flexible generalized minimal residual(FGMRES)method. 展开更多
关键词 block triangular splitting block two-by-two linear systems Eigenvalues PRECONDITIONER flexible generalized minimal residual(FGMRES)
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A Novel Decoder Based on Parallel Genetic Algorithms for Linear Block Codes
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作者 Abdeslam Ahmadi Faissal El Bouanani +1 位作者 Hussain Ben-Azza Youssef Benghabrit 《International Journal of Communications, Network and System Sciences》 2013年第1期66-76,共11页
Genetic algorithms offer very good performances for solving large optimization problems, especially in the domain of error-correcting codes. However, they have a major drawback related to the time complexity and memor... Genetic algorithms offer very good performances for solving large optimization problems, especially in the domain of error-correcting codes. However, they have a major drawback related to the time complexity and memory occupation when running on a uniprocessor computer. This paper proposes a parallel decoder for linear block codes, using parallel genetic algorithms (PGA). The good performance and time complexity are confirmed by theoretical study and by simulations on BCH(63,30,14) codes over both AWGN and flat Rayleigh fading channels. The simulation results show that the coding gain between parallel and single genetic algorithm is about 0.7 dB at BER = 10﹣5 with only 4 processors. 展开更多
关键词 CHANNEL Coding linear block Codes META-HEURISTICS PARALLEL Genetic ALGORITHMS PARALLEL Decoding ALGORITHMS Time Complexity Flat FADING CHANNEL AWGN
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End-to-end verifiable electronic voting scheme of blockchain based on random linear block code
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作者 Liu Ting Cui Zhe +1 位作者 Pu Hongquan Peng Xingyi 《High Technology Letters》 EI CAS 2020年第1期25-33,共9页
Blockchain is an emerging decentralized technology of electronic voting.The current main consensus protocols are not flexible enough to manage the distributed blockchain nodes to achieve high efficiency of consensus.F... Blockchain is an emerging decentralized technology of electronic voting.The current main consensus protocols are not flexible enough to manage the distributed blockchain nodes to achieve high efficiency of consensus.For practical implementation,the consensus based on random linear block code(RLBC)is proposed and applied to blockchain voting scheme.Along with achieving the record correctness and consistency among all nodes,the consensus method indicates the active and inactive consensus nodes.This ability can assist the management of consensus nodes and restrain the generating of chain forks.To achieve end-to-end verifiability,cast-or-audit and randomized partial checking(RPC)are used in the proposed scheme.The voter can verify the high probability of correctness in ballot encryption and decryption.The experiments illustrate that the efficiency of proposed consensus is suitable for blockchain.The proposed electronic voting scheme is adapted to practical implementation of voting. 展开更多
关键词 RANDOM linear block code(RLBC) ELECTRONIC voting(e-voting) blockchain CONSENSUS END-TO-END verifiable
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A New Preconditioner with Two Variable Relaxation Parameters for Saddle Point Linear Systems with Highly Singular(1,1) Blocks
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作者 Yuping Zeng Chenliang Li 《American Journal of Computational Mathematics》 2011年第4期252-255,共4页
In this paper, we provide new preconditioner for saddle point linear systems with (1,1) blocks that have a high nullity. The preconditioner is block triangular diagonal with two variable relaxation paremeters and it i... In this paper, we provide new preconditioner for saddle point linear systems with (1,1) blocks that have a high nullity. The preconditioner is block triangular diagonal with two variable relaxation paremeters and it is extension of results in [1] and [2]. Theoretical analysis shows that all eigenvalues of preconditioned matrix is strongly clustered. Finally, numerical tests confirm our analysis. 展开更多
关键词 SADDLE Point linear Systems block TRIANGULAR PRECONDITIONER Krylov SUBSPACE Methods
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A Generalized Block-by-block Method for the System of Linear Volterra Integral Equations of the Second Kind
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作者 WANG Wenshuai WANG Xu 《Wuhan University Journal of Natural Sciences》 CAS 2011年第6期465-468,共4页
In this paper, we provide a generalized block-by-block method for constructing block-by-block systems to solve the system of linear Volterra integral equations of the second kind, and then deduce some of the special c... In this paper, we provide a generalized block-by-block method for constructing block-by-block systems to solve the system of linear Volterra integral equations of the second kind, and then deduce some of the special cases. Compared with the expansion method and He's homotopy perturbation method, respectively numerical examples are given to certify the effectiveness of the method. The results show that the block-by-block method is very effective, simple, and of high accuracy in solving the system of linear Volterra integral equations of the second kind. 展开更多
关键词 block-by-block method the system of linear Volterraintegral equations numerical solution
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对LBlock算法的多重零相关线性分析 被引量:5
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作者 罗芳 周学广 欧庆于 《西安电子科技大学学报》 EI CAS CSCD 北大核心 2014年第5期173-179,共7页
为了降低对LBlock进行零相关线性分析所需的数据复杂度,提出了对LBlock进行多重零相关线性分析的方法,证明了14轮LBlock存在26条零相关线性逼近,并给出了其具体构造.利用26条14轮零相关线性逼近为区分器,并基于正态分布的概率计算模型... 为了降低对LBlock进行零相关线性分析所需的数据复杂度,提出了对LBlock进行多重零相关线性分析的方法,证明了14轮LBlock存在26条零相关线性逼近,并给出了其具体构造.利用26条14轮零相关线性逼近为区分器,并基于正态分布的概率计算模型对22轮LBlock进行了多重零相关线性攻击,攻击的数据复杂度约为263.45个已知明文,计算复杂度约为276.27次22轮LBlock加密,成功实施攻击的概率为0.85.结果表明,该方法有效解决了需要利用整个明文空间对LBlock进行零相关线性分析的问题. 展开更多
关键词 轻量级分组密码 Lblock算法 多重零相关线性逼近 密码分析 数据复杂度
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储存温度与时间对SiO_(2)/芥酸酰胺复合改性LLDPE薄膜爽滑开口性能的影响
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作者 邓祖豪 夏霜 +2 位作者 石璞 王芳可 缪星星 《包装学报》 2026年第2期26-32,共7页
针对线型低密度聚乙烯(LLDPE)薄膜在实际应用中因高温或长期储存导致爽滑开口性能下降的问题,通过双螺杆挤出机制备LLDPE/芥酸酰胺和LLDPE/SiO_(2)/芥酸酰胺母粒,使用吹膜工艺制备含有不同比例LLDPE的LLDPE/SiO_(2)/芥酸酰胺薄膜,并进... 针对线型低密度聚乙烯(LLDPE)薄膜在实际应用中因高温或长期储存导致爽滑开口性能下降的问题,通过双螺杆挤出机制备LLDPE/芥酸酰胺和LLDPE/SiO_(2)/芥酸酰胺母粒,使用吹膜工艺制备含有不同比例LLDPE的LLDPE/SiO_(2)/芥酸酰胺薄膜,并进一步考察了不同储存时间及温度条件对薄膜爽滑开口性能和光学性能的影响。研究表明,芥酸酰胺可显著降低LLDPE薄膜的静摩擦系数(μ_(s))和动摩擦系数(μ_(k)),SiO_(2)与芥酸酰胺的协同效应则能有效解决单一爽滑剂在高温或长期储存下开口性能衰减的问题。当SiO_(2)含量为0.199%时,薄膜在-10, 25, 50℃下均表现出优异的爽滑性能,且开口性能稳定可靠。SiO_(2)均匀分散在LLDPE/SiO_(2)/芥酸酰胺母粒和薄膜中,并作为LLDPE薄膜的成核剂,实现了LLDPE薄膜开口爽滑性能的长期稳定调控。 展开更多
关键词 线型低密度聚乙烯 二氧化硅 芥酸酰胺 开口剂 爽滑开口性能
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30轮LBC-IoT算法的线性分析
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作者 李灵琛 陈佐甲 +1 位作者 韦永壮 叶涛 《通信学报》 北大核心 2026年第2期209-218,共10页
为了评估LBC-IoT算法抵抗线性分析的能力,基于MILP自动化搜索技术,同时采用直接搜索和迭代线性逼近循环构建两种方法求解轮数最长的线性逼近集合,并在扩展轮数尽可能长的情况下得到每一条线性逼近的初始密钥猜测基。进一步结合最小猜测... 为了评估LBC-IoT算法抵抗线性分析的能力,基于MILP自动化搜索技术,同时采用直接搜索和迭代线性逼近循环构建两种方法求解轮数最长的线性逼近集合,并在扩展轮数尽可能长的情况下得到每一条线性逼近的初始密钥猜测基。进一步结合最小猜测基技术对初始密钥猜测基进行压缩,以此筛选出最优线性逼近进行密钥恢复攻击。结果表明,LBC-IoT算法共有6条线性偏差为2^(-15)的23轮线性逼近,其中存在唯一一条最小猜测基仅为52 bit的最优线性逼近。基于该区分器向上和向下分别扩展3轮和4轮,首次对LBC-IoT算法发起了最长30轮的密钥恢复攻击。该攻击的数据、时间和存储复杂度分别为2^(30)个已知明文、2^(77.9)次30轮加密和2^(52)。相比已有结果,攻击轮数整体提升了4轮,导致LBC-IoT算法的安全冗余轮数不足7%,不建议用于实际的通信数据加密。 展开更多
关键词 轻量级分组密码 LBC-IoT算法 线性分析 最小猜测基
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TWO ALGORITHMS FOR SYMMETRIC LINEAR SYSTEMS WITH MULTIPLE RIGHT-HAND SIDES 被引量:4
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作者 戴华 《Numerical Mathematics A Journal of Chinese Universities(English Series)》 SCIE 2000年第1期91-110,共20页
In this paper, we investigate the block Lanczos algorithm for solving large sparse symmetric linear systems with multiple right-hand sides, and show how to incorporate deflation to drop converged linear systems using ... In this paper, we investigate the block Lanczos algorithm for solving large sparse symmetric linear systems with multiple right-hand sides, and show how to incorporate deflation to drop converged linear systems using a natural convergence criterion, and present an adaptive block Lanczos algorithm. We propose also a block version of Paige and Saunders’ MINRES method for iterative solution of symmetric linear systems, and describe important implementation details. We establish a relationship between the block Lanczos algorithm and block MINRES algorithm, and compare the numerical performance of the Lanczos algorithm and MINRES method for symmetric linear systems applied to a sequence of right hand sides with that of the block Lanczos algorithm and block MINRES algorithm for multiple linear systems simultaneously.[WT5,5”HZ] 展开更多
关键词 SYMMETRIC matrices multiple linear SYSTEMS block LANCZOS algorithm block MINRES method.
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A Method for Improving Power Distribution Characteristics of Space Time Block Codes 被引量:3
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作者 Vahid Abbasi Mahrokh GShayesteh 《China Communications》 SCIE CSCD 2020年第6期223-234,共12页
Improving power distribution characteristics of space time block codes(STBCs),namely peak to average power ratio(PAPR),average to minimum power ratio(Ave/min),and probability of transmitting"zero"by antenna,... Improving power distribution characteristics of space time block codes(STBCs),namely peak to average power ratio(PAPR),average to minimum power ratio(Ave/min),and probability of transmitting"zero"by antenna,makes easier their practical implementation.To this end,this study proposes to multiply full diversity STB C with a non-singular matrix in multiple input multiple output(MIMO)or multiple input single output(MISO)systems with linear or maximum likelihood(ML)receivers.It is proved that the obtained code achieves full diversity and the order of detection complexity does not change.The proposed method is applied to different types of STBCs.The bit error rate(BER)and power distribution characteristics of the new codes demonstrate the superiority of the introduced method.Further,lower and upper bounds on the BER of the obtained STBCs are derived for all receivers.The proposed method provides trade-off among PAPR,spectral efficiency,energy efficiency,and BER. 展开更多
关键词 full diversity linear receiver maximum likelihood peak to average power ratio power distribution space time block codes
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多维零相关线性分析模型的改进及在23轮LBlock-s算法中的应用 被引量:1
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作者 李灵琛 吴文玲 汪艳凤 《计算机学报》 EI CSCD 北大核心 2017年第5期1192-1202,共11页
基于相关性为零的线性逼近的多维零相关线性密码分析是目前最重要的分组密码分析手段之一.该文主要对多维零相关线性分析模型的密钥恢复阶段进行了深入的研究,通过定义等价密钥的距离来刻画等价密钥在压缩表达式中的位置关系,进一步约... 基于相关性为零的线性逼近的多维零相关线性密码分析是目前最重要的分组密码分析手段之一.该文主要对多维零相关线性分析模型的密钥恢复阶段进行了深入的研究,通过定义等价密钥的距离来刻画等价密钥在压缩表达式中的位置关系,进一步约简区分器候选集合同时优化密钥猜测顺序,从而改进了原有的多维零相关线性分析的攻击模型.改进的模型首先找到所有最长的多维零相关线性区分器,然后利用密钥编排算法求得密钥恢复阶段所涉及的独立猜测密钥量,以此筛选区分器候选集合.最后,根据等价密钥的距离对候选区分器进行再次筛选,同时得到相应的密钥猜测顺序.LBlock-s算法是CAESAR竞赛中所提交的认证加密算法LAC的核心分组算法.与Lblock算法不同,LBlock-s采用具有更快混淆速度的密钥编排算法.基于改进的优化模型,该文分析了该算法抵抗多维零相关线性攻击的能力.研究表明,攻击23轮LBlock-s算法所需的数据复杂度为2^(62.3)个选择明文,时间复杂度为2^(73.75)次23轮LBlock-s加密,存储复杂度为2^(56)字节.这是目前针对LBlock-s算法的最优攻击结果. 展开更多
关键词 分组密码 Lblock-s 多维零相关线性分析 逐步压缩技术 等价密钥
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